Paul Holmes-Higgin cefda8c965 Updated header to LGPL
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@18931 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261
2010-03-01 22:48:39 +00:00

77 lines
2.5 KiB
Java

/*
* Copyright (C) 2005-2010 Alfresco Software Limited.
*
* This file is part of Alfresco
*
* Alfresco is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Alfresco is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
*/
package org.alfresco.repo.cache;
import java.io.Serializable;
import java.util.Collection;
/**
* Basic caching interface.
* <p>
* All implementations <b>must</b> be thread-safe. Additionally, the use of the
* <tt>Serializable</tt> for both keys and values ensures that the underlying
* cache implementations can support both clustered caches as well as persistent
* caches.
* <p>
* All implementations must support <tt>null</tt> values. It therefore follows
* that
* <pre>
* (simpleCache.contains(key) == true) does not imply (simpleCache.get(key) != null)
* </pre>
* but
* <pre>
* (simpleCache.contains(key) == false) implies (simpleCache.get(key) == null)
* <pre>
*
* @author Derek Hulley
*/
public interface SimpleCache<K extends Serializable, V extends Object>
{
/**
* @param key the cache key to check up on
* @return Returns <tt>true</tt> if there is a cache entry,
* regardless of whether the value itself is <tt>null</tt>
*/
public boolean contains(K key);
public Collection<K> getKeys();
/**
* @param key
* @return Returns the value associated with the key. It will be <tt>null</tt>
* if the value is <tt>null</tt> or if the cache doesn't have an entry.
*/
public V get(K key);
/**
* @param key the key against which to store the value
* @param value the value to store. <tt>null</tt> is allowed.
*/
public void put(K key, V value);
/**
* Removes the cache entry whether or not the value stored against it is <tt>null</tt>.
*
* @param key the key value to remove
*/
public void remove(K key);
public void clear();
}